The use of well installations having orienting means for selectively installing or removing well apparatus from a well sub in well tubing is old as illustrated in U.S. Pat. Nos. 3,827,490; 2,942,671; 2,948,341; and 2,988,146. However, in the prior art in order to install or remove well apparatus selectively in one of a plurality of well subs in a well tubing, multiple reciprocation of the well locator tool in the tubing is required. However, multiple reciprocation of a well tool at definite locations in a tubing, particularly in a hydraulic pumpdown system, is difficult to perform and is therefore undesirable. One feature of the present invention is the actuation of a well locator tool in a well tubing by a single down and up movement by engaging an upwardly directed shoulder in the well tubing thereby avoiding multiple reciprocation of the locator tool. Another feature of the present invention is the provision of providing different configurations in a plurality of well subs whereby a particular well tool will selectively coact only with a selected well sub. Another feature of the present invention is that the selectivity is provided by a configuration of ridges and valleys in a slot in the well sub which avoids providing obstructions in the well tubing upon which other well equipment having annular shoulders may engage. In addition, the present invention provides a well installation having various other improvements in which well apparatus is selectively installed or removed from one of a plurality of well subs in the well tubing.